soc/intel/alderlake: Remove pch.h from SoC directory

Remove unnecessary include of soc/pch.h from
- bootblock/pch.c
- bootblock/report_platform.c
- bootblock/uart.c

Define PCIE_CLK_XXX macro inside chip.h for mb/devicetree.cb to
consume.

Change-Id: Ic08ef586d4590462434ba2c64e21dd802ccc6800
Signed-off-by: Eric Lai <ericr_lai@compal.corp-partner.google.com>
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/50132
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/alderlake/uart.c

@@ -13,7 +13,6 @@
 #include <intelblocks/pcr.h>
 #include <intelblocks/uart.h>
 #include <soc/iomap.h>
-#include <soc/pch.h>
 #include <soc/pci_devs.h>
 #include <soc/pcr_ids.h>